Extending drain intervals on a heavy duty diesel engine can produce real savings in terms of reduced costs and downtime. In some cases, engine manufacturers are allowing up to 80,000 miles between drain intervals. For many over-the-road fleets, that would make changing the oil and filter an annual event — an unheard-of proposition only a few years ago.
But moving beyond a drain interval of 20,000 or 30,000 miles is a huge step for many fleets who remain unconvinced or unaware of the benefits, even if the engine manufacturer recommends it. Everyone wants to save money on oil, filters, labor, and disposal fees, but doubling or tripling the mileage or time between changes may seem risky.
For fleets thinking about extending drain intervals, there are some important factors to consider.
How a fleet manages oil drain intervals is tied to how they use and maintain the truck. It’s one of the first questions we ask when we talk to fleets about their service schedules. Not every application or duty cycle conforms to a conventional drain schedule, especially when it involves seasonal work, heavy hauling, or a high percentage of idle time. Fleets will want to assess how an extended oil drain interval will align with preventive maintenance for other components including air filters, gaskets, chassis parts that require grease, and the engine’s cooling and fuel systems.
Fleets would also need to coordinate service events or truck downtime with regular sampling for an oil analysis program, which engine manufacturers require in order to preserve full warranty coverage during extended drain intervals.
Then there is the oil itself. The latest formulations promise better oxidation stability, shear stability, resistance to aeration, and greater overall durability at higher operating temperatures, which makes them well-suited to extended use. Anything that helps oil last longer is going to help the filter last longer too, as long as it can handle prolonged exposure to vibration, pressure cycles, and temperature changes while still capturing the particles that can wear down pistons, rings, and bearings.
There’s more to extending drain intervals than just adding miles or hours between changes, which is why fleets tend to be cautious about whether it’s right for them. If a fleet is planning an extended oil drain interval program, here are four things to consider to be sure your oil, filter, and maintenance practices are ready for the long haul.
1. Lubricants
Most shops today are managing two formulations of heavy duty engine oils: API FA-4 and API CK-4. The main difference between the two is that FA-4 oils were developed for 2017 model year and later engines only in order to provide maximum fuel economy and a lower viscosity for better cold-weather performance. CK-4 engine oils are designed for newer late model engines but are also backward compatible.
If a fleet has a mix of older and newer trucks, they may need distinct extended-drain interval programs for each classification of lubricant. Putting an FA-4 oil in a non-FA-4 compliant engine won’t cause long-term harm, but it should not be a common practice, and fleets should expect that it will affect the results of their oil analysis program.
As always, check with the engine manufacturer about which formulations are approved for extended drain intervals. If the manufacturer allows CK-4 for extended drains on its latest model-year engines, fleets can use one oil in their extended drain program and greatly simplify the process.
2. Filter media
Oil is commonly referred to as the “lifeblood” of the engine. In this vital system, the engine oil filter acts as a kidney: It protects the engine by capturing and removing harmful contaminants from the oil through the service interval.
For extended drains, high filter efficiency is important for effectively removing the contaminants that are known to wear down engine components. The filter needs to have the capacity to hold this contaminant throughout the desired service interval and beyond. Finally, low flow restriction not only improves fuel economy by taking the strain off the oil pump, but it also means faster lubrication of critical components on engine start-up.
The latest polymeric media has uniform porosity and fiber integrity that will not degrade over the life of the filter. Polymeric fibers are bonded together for durability and, compared to other synthetic media materials, are far less prone to degrading and passing fibers downstream into the engine. They’re robust and effective — an ideal choice for a long-life lube filter.
Like engine oil, it’s essential that fleets follow the engine manufacturer’s recommendations for replacement filters. The aftermarket is full of filters that look the same on the outside but on the inside will fail to meet specifications for the drain intervals a fleet is trying to achieve. It’s worth asking who makes your lube filters and the media in particular. Are they manufactured with dependable production quality and materials? Saving a few dollars with cheap filters or “will-fit” products may ultimately cost much more in component wear, shorter engine life, and expensive repairs.
3. Condition-based monitoring
Nearly every major engine manufacturer has its own platform for remote diagnostics or supports the use of third-party OBD-connected telematics devices (or both). These connected services streamline the collection and communication of engine data: sensors, control modules, and telematics on the vehicle can monitor fault codes, prioritize them, and send alerts to a fleet’s maintenance management system or mobile app. This allows the fleet to make decisions on what to do next without waiting to bring the vehicle into the shop.
Engine filtration is a natural fit for condition-based monitoring technology. A system of on-filter sensors, control modules, and telematics can provide data about a filter’s performance and the remaining oil and filter life based on actual operating conditions. The obvious benefit is that fleets can reduce the risk of changing the oil or filters before their usable life is up. Conversely, fleets can be alerted when a problem crops up in between oil changes—say, a filter plugs prematurely or perhaps isn’t delivering the expected performance.
Cummins Filtration first offered condition-based filter monitoring in 2018. Its FleetguardFIT system uses pressure sensors to monitor restrictions in oil, fuel, and air filters, and a fluid sensor to determine the remaining life of the oil. A control module collects the data, and a telematics device transmits it to the cloud for analysis and viewing via a web portal or a mobile device app. FleetguardFIT is an aftermarket product and takes only a few hours per vehicle to install. It’s exclusive to Fleetguard filters but can be installed on any OEM engine or engine size.
4. Oil analysis
The condition of a fleet’s filters tells only part of the story when it comes to extending drain intervals. The oil itself is a key component, and fundamental to the durability of an engine’s pistons, rings, and bearings.
A comprehensive lab analysis is an effective way to determine an optimal lube interval because it accounts for operating conditions, maintenance practices, the quality of oil used, and other variables that are specific to a fleet’s vehicle’s engine.
For example, the lab may show that a fleet’s vehicle’s oil has plenty of life in it at 30,000 miles. The fleet may receive a recommendation to try increasing the drain interval to 50,000 miles, sending another sample for analysis at that point.
Or, an engine manufacturer may offer the option to safely extend oil change intervals while keeping full warranty coverage. Some OEMs provide this analysis free of charge. The Fleetguard OilGuard program also includes free analysis. It’s vital to make sure fleets are getting an accurate, consistent, and thorough analysis, which means regular submission of engine data and oil samples to a reputable lab for the benefit of full warranty coverage throughout an extended drain interval.
Conclusion
No matter what oil drain interval a fleet uses, the same best practices apply:
- Following the engine OEM’s recommendations will help get the performance a fleet expects from the engine oil and filter.
- Fleets should spec the proper efficiency filter for the application and use the highest-quality oil available, especially if planning to extend drain intervals.
- Oil analysis and condition-based monitoring are essential for extending drain intervals because a fleet’s trucks are spending more time on the road before they come in for maintenance. Plus, there’s no better combination for optimizing the service intervals for a fleet’s specific engine and operation.
Finally, talk to engine, lubrication, and filter suppliers. They can help fleets make an informed choice about which oil and filter are best for a specific operation, and will benefit, too, from learning more about what kind of performance fleets expect between oil changes.
Chris Alley is the global product manager, lube & air filtration for Cummins Filtration. Ismail Bagci is chief engineer, GOE liquid engineering for Cummins Filtration.
